A large number of services are available to users on the Internet, including social media platforms, e-commerce sites, news and commentary services, online gaming platforms, and others. Also, many services that exist primarily separately from the Internet, such as so-called brick-and-mortar businesses, have established a presence on the Internet to sell goods and services online, advertise their goods and services, and otherwise connect with existing and potential customers. In both examples, attracting new users to register with or otherwise use a service can be crucial to the success of the service. Moreover, the value of various types of services may be determined, at least in part, by a network effect whereby the value of the service increases (e.g., linearly or in some instances exponentially) as the service attracts and maintains a larger user population. Accordingly, services seek new ways to build their user base and thus survive and grow.